Unsteady numerical simulations of single-phase turbulent mixing in tight lattice geometries

This paper focuses on the unsteady numerical simulations of the turbulent flow in tight lattice geometries with the explicit algebraic Reynolds stress model. The calculation results showed that the shape of the geometry, gap width and rod diameter as well as the Reynolds number were important parameters that would influence the characteristics of the flow (such as the dominant frequency and wavelength of the pulsation) and the turbulent mixing between the subchannels. And a modified correlation of turbulent mixing was proposed, which showed better agreement with the past experimental results compared to the other existing correlations, especially for the low Prandtl number fluids such as liquid sodium.

► Simulate the flow and turbulent mixing in tight lattice geometries. ► Unsteady numerical simulation with modify explicit algebraic Reynolds stress model. ► Propose new correlations of the turbulent mixing coefficient. ► The new correlations agree well with the experimental results.